This invention is directed to the provision of an integrated circuit controller chip especially adapted for use in Echoplex communication, and that can be also employed in some RS232 communication.
Echoplex communication is discussed below, and also described in U.S. Pat. No. 4,535,421, Duwel et al, and U.S. Pat. No. 4,410,961, Dlugos et al. This communication protocol has been found to be of particular use in postage meter systems, although it is also useful for other communication.
Various techniques has been employed in the part for interfacing employing the Echoplex protocol. Thus, U.S. Pat. No. 4,535,421, Duwel et al, enables communication between a host computer and a postage meter employing a microprocessor with a control program, and a peripheral interface processor also having a control program. U.S. Pat. No. 4,395,756, Daniels; U.S. Pat. No. 4,410,961, Dlugos et al, and U.S. Pat. No. 4,410,962, Daniels et al disclose an interface system employing a microcomputer as well as hard wired logic. U.S. Pat. No. 4,642,791, Mallozzi et al discloses an interface to a weighing system, also employing a microcomputer.